Piston expander



Aug. 14. 192s.

F. A. TRAVIS4 PISTON EXPANDER Filed Sept. 12. 1927 2 Sheets-Sheet 2 Summum 5 Trank ./Z j''avzlf,

Imam l WJ; nes; 60M WM,

Patented Aug. 174, 1928.

UNITED STATES FRANK A. TRAVIS, OF KANSAS CITY, MISSOURI.

PISTON EXPANDER.

Application led September 12, 1927. Serial No. 218,938.

My invention relates to piston expanders and one object is to provide a simple and eilicient device of this character whereby enine pistons which have become worn can ge expanded to their original diameters at very little cost. y

A further object is to provide a device of this character with a wide range of adjustment so that it can be employed to advantage in expanding pistons of different diameters. w

In order that the invention may be fully understood, reference will now be had tothe accompanying drawings, in which:

Fig. l is a broken elevation partly in section of the device.

Fig. 2 is adetail of the piston clamping and expanding mechanism.

Fig. 3 is an inverted plan view of the parts disclosed by Fig. 2, with the wedge member of the expanding mechanism re` of the yoke 4 are held by pins 8 which may be withdrawn to permit removal of said yoke when it is desired to place the expanding mechanism, hereinafter described, within a piston.

10 designates a piston clamping member which is preferably of conical formation forA engaging the open ends of pistons to be expanded. The conical member 10 is surmounted by an axially vdisposed neck 12y having a superimposed head 14 adapted to be engaged and rotated by a suitable wrench. A central bore 16 extends through the conical member 10, the neck 12 and the head 14 and is threaded at its upper portion upon a tubular member 18 provided at its upper end with a peripheral flange 20 which is journaled in a bearing 22 secured to the upper portion of the yoke 4. A peripheral shoulder 24 is formed on the upper portion of the tubular member 18 so that it may be grasped by hand or held with a wrench while the conical member is being screwed up or down.

The expanding mechanism for expanding the pistons includes a pair of blocks 26 and a wedge member 28. The wedgeV member 28 isv slidably mounted in vupwardly tapered grooves 30 formed within the adjacent sides of the blocks 26, which latter are yieldably held together by suitable .meansl such as coil springs 32. The wedge member 28 is prevented from moving laterally in any direc- `tion by flanges 34 and 36 forming sides of the grooves 30. The blocks 26 are provided at their upper portions with dovctail grooves 34a for the reception of a complementary tongue 36%extending across the bottom of the conical member 10 for the purpose of supporting the blocks 26.

lhe narrow'faces'SS of the blocks 26 are curved as shown by Figs. 3 and 4, `to avoid presenting .sharp corners to the interior of the pistons to be expanded.

The wedge member `28 of the expanding mechanism is raised and lowered by means of a stem 40, the lower portion ofwhich is threaded into aA bore 42 extending centrally of the wedge member 28. `The stem 40 extends axially through the tubular member-18 and is -journaled at its upper Vportion in the upper central portion of the yoke 4, where it is held from longitudinal movement by a collar 42 bearing against the under surface and a peripheral shoulder 44 bearing against the upper surface of the upper transverse portion of the yoke 4. The upper enlarged end of the 'stem 40 is provided with a handle 46 whereby said stem may be rotated to raise or lower the wedge member 28.

In order that the pistons may be accurately expanded to a predetermined diameter, I provide gage means consisting of thumb screws 48 threaded in the opposite sides of the yoke 4.

In practice when a piston such as A is to be expanded diametrically, it is placed in an inverted position upon the base 2. The yoke 4 which was previously removed from the base 2 to allow the expanding mechanism to be inserted within the piston is then relaced, after which the piston is clamped rmly in position upon said base by properadjustment of the conical member 10-and the tubular member 18. The handle 46 is then rotated in the proper direction to raise. the Wedge member 28 which forces the blocks 26 outwardly far enough to engage the inner Surface of the cylindrical wall of the piston A and expand said wall diametrically until checked by the gages 48 which were previously spaced apart the proper distance.

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After the piston has been expanded as stated, the conical member 10 is adjusted upwardly out of engagement with said piston to relieve the pressure thereon, after which the pins 8 are withdrawn to permit removal 'of the yoke 4 and the expanding mechanism, A

Expansion of the iston is facilitated when the same is in a highly heated condition. Owing to the wide range of movement of the expanding mechanism, it will be understood that pistons of diii'erent sizes can be expanded without changing blocks 26 and the wedge 28 for larger' or smaller sizes.

While I have shown the preferred form of my invention I reserve the right to all such 'changes inthe construction, combination and arrangementootl parts as properly fall within the spirit and scope of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:` Y

l. In a piston expander, means including a conical Inember for firmly holding a piston, threaded means upon which said conical member is adjustably mounted, elements operably supported by said conical member and adapted to be inserted within the piston, and mechanism for forcing saidfelements outwardly to effect expansion of the piston.

2. In a piston expander, means including a conical member for rmly holding a piston, elements having al tongue and groove connection with said conical member and adapted to be inserted within the piston, spring means for yieldably drawing said clements toward each other, and mechanism for forcing saidlelements apart to effect expansion of the' piston.

3. rIn a piston expander, a base for supporting a piston to be expanded, a yoke kmounted upon'. said base, a rotary element depending from said yoke, a conical member threaded upon said rotary element for firmly holdingtlie piston upon the base, and piston-expanding mechanism associated with said rotary element and said conical menibcr.

4. In a piston expandcr,a frame, pistonexpanding mechanism associated with said frame, and gage means threaded in the opposite sides of said frame for limiting expansion of the piston.

5.l A piston' expander' consisting of' a base, a yoke supported by said base, a threaded tubular member supported by the yoke, a conical member adjustably mounted upon said threaded member and adapted to hold the piston upon the base, a pair of blocks slidably connected to saidV conical member and adapted to be inserted within the piston, a wedge member forforcing said blocks in opposite directions to effect expansion of tbc piston, and a stem journaled in the yoke extending through said tubular member and threaded in said wedge member for actuating the latter.

In testimony whereof I afx my signature.

- FRANK A. TRAVIS. 

